After years of fiddling around and too often failing, there are definite signs of improvement in my propagating. And so there should be considering the number of workshops attended and books read. Here, because it might save you time if you are starting off and I might forget, are the tips I have found useful over recent years.
First of all is the question of what to sow seeds in. At the start, I bought a whole stack of full sized seed trays. A mistake. These tempted me to scatter the whole surface with seeds. This meant ending up with far too many seedlings (if they all germinated) or wasting a whole packet of seed and time. Those trays also took lots of room which was precious when I only had a couple of cold frames. For me, even half a seed tray is usually too much and the quarter size ones are just about perfect for most seeds. I can fit four times as many in the same space and feed my seed sowing obsession by sowing many more varieties. For larger seeds, I use and reuse module trays; these are brilliant for pricking out small seedlings too.
The sowing medium is obviously key and despite all the advice about specialist seed compost I have resolutely stuck with peat free multi purpose compost. Now perlite or grit might be added, but the best choice for me over the last few years has been Silva Grow which is always on offer (5 bags for 4) at local builders merchant. It is light and well composted and I have never had a bad bag.
Nasturtium Tip Top growing happily in a module tray filled with Silva Grow peatfree compost
Filling the seed tray up to the top, tapping gently on a bench to remove air pockets and firming down the surface of compost has become a habit. Obviously, sowing seeds thinly to give them room is important and for me, with small seeds, still a work in progress. For years, after sowing the seeds I would cover them with a sprinkling of compost, but now a light dusting of vermiculite is usually how I top the tray off. Grit a la Carol Klein is very satisfying, but I don’t always have it.
In the past I would then drench the carefully sown seeds by watering them from the top with a watering can, but now the trays are put in a tray of water to soak up water and when the top looks damp they are taken out. At least that is the idea. Honestly lots are left too long, but it doesn’t usually matter. At least unintended heavy drops of water from a watering can rose doesn’t wash them away.
Also, in the past I would have forgotten the crucial stage of labelling, thinking I would remember. Of course I most often didn’t and would have to try to work out what was what from emerging leaves. White plastic labels seem to get everywhere, but they are an essential part of this process. Once they have been used up, I might try a non-plastic option, but for now reusing them as many times as possible has to be a good enough environmental compromise. And while pencil works, I prefer a permanent marker pen as it’s easier to read.
The courses last year offered many propagating tips which debunked popular gardening wisdom. The first one was that it isn’t always essential to wait for the seedling’s true leaves to appear before pricking out. Have tried this and have been nicely amazed that it doesn’t seem to make any difference. The second was not to bother with hormone rooting powder and this is one I am experimenting with.
Seeds should be used up year on year and fresh bought in annually and keeping them in a sealed container in the fridge would be the ideal, but I don’t live alone and compromises on this front have to be made. It is surprising how many neglected and badly stored packets germinate cheerfully, but I would certainly avoid disappointment if I improved this part of the process.
No matter how often I sow seeds, the pleasure of seeing the first one in a tray push through the compost surface never gets stale. Nobody needs to tell me how lucky I am to have acquired a greenhouse, but I am genuinely surprised by how quickly it fills up.